From the River Kelvin in Glasgow; also associated with Lord Kelvin the physicist.
Kelvin began as a Scottish place-name and surname before becoming a given name. The River Kelvin runs through Glasgow, and the title “Lord Kelvin” was taken from that river by the physicist and engineer William Thomson, one of the great scientific figures of the nineteenth century. His work in thermodynamics and absolute temperature fixed the name permanently in scientific language through the kelvin, the SI unit of thermodynamic temperature.
That gives Kelvin an unusual dual identity: it is both personal name and scientific vocabulary. As a first name, Kelvin seems to have grown partly through that association with precision, intellect, and modernity. It fits the pattern of surnames becoming given names, especially in English-speaking countries, but it also benefited from the prestige of science.
Parents may not always choose it because of Lord Kelvin specifically, yet the name quietly carries that aura of rigor and invention. Across the twentieth century it found steady use in Britain, the Caribbean, parts of Africa, and the United States, where it came to sound familiar without ever becoming overused. Its perception has evolved in interesting ways.
Once it may have seemed distinctly scholarly or formal; now it often feels clean, international, and versatile. In popular culture it has been borne by athletes, musicians, and public figures, which has broadened it beyond its scientific frame. Still, the temperature unit shadows it in the most interesting way: Kelvin is one of the few names that can evoke both a human biography and a whole system of measuring the physical universe.